"Brazil's Labor Ministry Shuts Down Waste Piles at the Country's Largest Lithium Miner", 15 January 2026

...Brazil’s Ministry of Labor and Employment (MTE) has confirmed the shutdown of three of the five waste and overburden piles operated by Sigma Lithium, the country’s largest lithium miner, effectively halting its mining operations. The structures, located in the Jequitinhonha Valley in the state of Minas Gerais, have safety factors below 1.3—the minimum required threshold—posing a risk of collapse.

The piles, which have been shut down since December, are 40 meters high and, if they were to fail, could hurl material up to 120 meters, potentially reaching the Piauí River and nearby communities. Auditors found partial ruptures in the structures, which are located behind a preschool. The decision was upheld by the MTE’s general appeals office, leaving the company with the option to comply or challenge the ruling in court.

Unlike tailings dams, Sigma stores its waste in piles. However, auditors warned that a collapse could cause impacts similar to the disasters in Brumadinho and Mariana.

In a statement sent to Folha, Sigma said its piles meet established safety parameters and that these conditions are being demonstrated to ministry technicians...